Insulated flanged wheel



Aug. 20,1963 1 1 H. TALBOYS 3,1 1, 4

' INSULATED FLANGED WHEEL Filed June 2, 196; I 3 Sheets-Sheet 1 By par/hr [far/a) fi/formq s.

H. H. TALBOYS I INSULATED FLANGED WHEEL Aug. 20, 1963 s Sheets-sheaf; 5

Filed June 2 ,1 1961 FIGURE 2,

United States Patent INSULATED FLANGED WHEE Henry H. Talhoys, deceased, late of Milwaukee, Wis., by

Doris Chisholm Talhoys, executrix, Milwaukee, Wis., assignor to Nordherg Manufacturing Company, Milwaukee, Wis.

Filed June 2, 161,-Ser. No. 114,560

2 Claims. (Cl. 295-1) This invention relates to an insulated railroad wheel of the type commonly used on railroad track working equipment. This application is a continuation-in-part of copendi-ng application, Serial No. 29,619, filed May 17, 1 960, and now abandoned. I

One purpose of this invention is a railroad wheel of the type described having a nonconductive insulating plastic annulus between the outer rim of the wheel and the inner hub. 7

Another purpose is I211]. insulated wheel structure, suitable for use on railroads or the like, in which the in sulating material is sufficiently strong to support-the machine or car.

Another purpose is a wheel of the type described having improved means for providing both an axial and a circumferential interlock between the metal parts of the wheel.

Another purpose is an insulated railroad wheel 'of the type described in which a plastic annulus forms the insulation betweenthe hub and the rim of the wheeLthe invention further including a means for compensating for shrinkage upon solidification of the plastic annulus.

Another purpose is an improved methodyo'f forming an insulated railroad wheel of the type described.

Other purpose will appear in the ensuing specification, drawings and claims. I Y

The invention is illustrated diagrammatically in the fol lowing drawings wherein:

FIGURE -1 is an end view of one form of insulated nailroad wheel, v

FIGURE 2 is a section along plane -H of FIG- URE l, v

FIGURE 3 is an end view taken along plane 3-3 of FIGURE 4 is a side view of the wheel hub shown in FIGURES l-3, 1

FIGURE 5 is an end view of the wheel rim shown in FIGURES l and 2,

FIGURE 6 is a section along plane 66 of FIGURE 5; FIGURE 7 is an end view of a second form of insulated railroad wheel, and

FIGURE 8 is a section along plane 88 of FIGURE 7.

Track working equipment may be used on a section of railroad line while the line is in operation. It is therefore necessary that some means be provided on the track equipment to prevent the railroad signaling system from being operated. If conventional railroad wheels are used on the track equipment, the metal wheels and axle form a short circuit between opposite rails and hence operate the signals. Accordingly, insulating means'are provided on the wheels'to prevent a short circuit between the rails.

It has been the practice in wheel structures of this general type to use an expensive bolt connection between the innerand outer Wheel sections with pressed fiber for 3,101,214 Patented Aug. 20, 1963 insulation. Previously, there wasused a rubber layer between the inner and outer wheel sections. Such a rubber layer was unsatisfactory as it deteriorated. Also it did not provide sufiicient compressive strength and furthermore was to some extent resilient, giving a bouncy eifect to the track equipment, which is undesirable.

In FIGURE 1, a metal rim 10 may have 'a flange 12,

. as conventional, which extends around the periphery of 26 which has an outer diameter less than the diameter of the bore, these diameters being measured at the farthest extent of the lugs. The outer surface of the hub 20 may have a plurality of lugs 22, which may be equally spaced or otherwise. The configuration of the 0uter=surface of the hub and inner surface of the rim-and the placement of these two members is such that the cavity or annulus defined therebetween preferably has a generally constant radial thickness. In other words, the lugs on the rim and hub are staggered so that the radial thickness of the annulus between the rim and hub is generally constant to provide an equal stress pattern. It is particularly advantageous to stagger the lugs on the rim and hub as this provides a strong and secure axial interlock. The hub is completed by an internal bore 24 which is used to mount the wheel on the axle.

In order to provide a circumferential interlock or to manner, a plurality of similar grooves may he formed in the internal surface of the rim, as at 28. When securing the hub and rim together, the grooves 26 may he placed in opposition to the grooves 28 or they may be staggered.

The grooves 26 and 28 may be generally triangular in form, as shown in the drawings, or they may be otherwise. For example, they may be square, round, elliptical,

etc. Instead of having grooves in both the rim and hub,

a groove in one and-a projection in the other may he provided, or projections in both may he provided. The

particular form of the circumferential interlock is not important.

- compressive strength. In addition it provides high shear The particular form of the lug on both the rim and the huh may vary. As shown in the drawings, the lugs or' teeth on the internal surface of the rim include a crest 30' and slanted side walls 32- and 34. This may vary. For example, these side walls could be straight, curved, arcularte or otherwise. What is important is to have a generally continuous lug which has suflicient thickness to provide a strong interlock (with the hub. The same is I true with the lugs formed on the outer surface of the hub.

The cavity defined between the rim. and hub may he- P'olyurethane is a filled with a suitable plastic material. suitable plastic as it is sufficiently rigid and has sufficient degrees F. Under ambient conditions,

strength which is important. One suitable type of polyurethane is that sold by Du Pont Company under the trademark Adiprene with a compound number of L-l 00.

FIGURE 7 shows :a further form of the invention including a rim 36 having a flange 3 8, as described before. The rirn 36 is somewhat cylindrical in form and includes an internal bore 40 within which is mounted a hub 4-2.. Both the rim and the hub are metal, as described before, and the outer diameter of the hut is less than the internal diameter of the rim to define a cavity 44. The hub may be completed by a generally central bore 46 having a key-way 48, the bore 46 providing a means for mounting the wheel on the axle of the car.

In order to provide an axial interlock between the rim and the hub, the outer surface of the hub may have a gradually decreasing diameter from a point generally adjacent the center of the cavity 44 toward the opposite sides. In a like manner, the internal diameter of the rim may gradually increase from a point generally adjacent the center toward the outside. In other words, the thickness of the cavity 44 gradually increases from a point generally adjacent the center of the cavity towards the outside. It is also within the scope of the invention to provide an annulus or cavity in which the thickness gradually decreases tfr'om a point adjacent the center towards the outside. In this case, there would be a reverse taper on both the rim and the hub. Preferably, the shape of the cavity is as shown. To further provide an axial interlock, a circumferentially-extending groove 50 may be formed in the outer surface of the hub adjacent the center and a similar circumferentially extendinggroove 52 adjacent the center of theinternal surface of the rim. These grooves may be aligned, as shown in FIGURE 8, or they may be otherwise.

To provide a circumferential interlock for the wheel shown in FIGURES 7 and 8, a plurality of circumferentially spaced grooves 54- may be formed in the internal surface of the rim and similar grooves 56 in the outer surface of the hub. These grooves may take any form and they may be aligned, as be otherwise.

In-both forms of the invention shown herein, the cavity or annulus defined between the rim and the hub is filled with a plastic, which is preferably polyurethane. This particular plastic hassufiicient strength to withstand the heavy load of the track equipment. In addition, polyurethane provides resistance to shocks. It is sufficiently rigid so that the track equipment will have a firm and steady support. The polyurethane, in liquid form, is poured into the cavity defined between the rim and hub and then is allowed to cure. Polyurethane may be oven cured in three hours at a temperature of between 18 -Z15 poly-urethane may shown in FIGURE 7, or they may curein about three weeks.

Polyurethane may shrink to a small extent, about 1.7 percent, upon solidification and curing. To compensate for this shrinkage, a plurality of holes 58 may be drilled in the plastic annulus 60. The holes are drilled prior to curing of the polyurethane, but after it has set sufiiciently to be worked. Pins 62, which are oversized, are then placed inthe holes 58. Preferably, the pins are formed of an electrically noneconductive material, for example nylon or the like.

In forming the wheel of FIGURES 7 and 8, after the polyurethane has set to a point where it can be drilled,

holes of a certain size are formed. Then nylon pins, which may, for example, be inch oversize in diameter, are placed in the holes. The polyurethanev is then allowed to cure for a period of about three weeks under normal conditions. As the polyurethane cures, it shrinks. However,

'as polyurethane-has plastic memory, and as the pins,

nylon or otherwise, were initially oversized, the shrinkage will be compensated for and the pins and annulus will be firm.

Considering the particular (form of cavity in FIGURES 7 and 8, shrinkage of the polyurethane provides a selfinsulated wheels for railroad track or the like. The wheel includes an outer metal rim and an inner metal hub, the outer diameter of the hub being less than the diameter of the rim' to define an annular cavity therebetween. The cavity is filled with a plastic, preferably polyurethane, which has sufiicient compressive and shear strength to adequately support the track working equipment. The polyurethane may include suitable fibers or fillers to add stren-gthand to increase the viscosity during pouring. The fibers or fillers also are effective to reduce shrinkage.

In order to provide both a circumferential and an axial interlock between the rim andfthe hub, a plurality of generally circumferentially extending lugs or teeth may be provided which are axially spaced on the outer sur- [face of the hub and the internal surface of the rim. Preferably, the lugs are positioned such that there is a cavity of constant thickness between the rim and hub to form a tortuous interlock. 1

In the form shown in FIGURES 7 and 8, the outer surface of the hub and the internal surface of the rim have been tapered such that the thickness of the cavity gradually increases from a point adjacent the center,

toward the outside. When thepolyurethane shrinks upon solidification and curing, it will merely move toward the center and still provide continuous contact between the and hub and hence continuous support.

In order to compensate *for the shrinkage upon solidification and curing of the polyurethane, a plurality of holes is provided in the polyurethane and oversized pins positioned within these holes. The pins are oversized and hence as the polyurethane shrinks, the plastic memory quality of the polyurethane will allow it to remain firmly around the pins. The oversized pins are elfective to compensate for the shrinkage of the polyurethane. Al-

though ;t-he oversized pins are shown in connection with the form of the invention of FIGURES l7 and 8,. this concept can also be used with the Wheel of FIGURES There are many variations for the particular structure shown herein. For example, axially extendinggrooves are shown in the internal surface of the rim and the outer surface of the hub 'inbothyforms of the invention for providing a circumferential interlock. Projections in both the rim and the hub may be used or a projection in one and a groove in the surface of the other may be used. The grooves orprojectionsi may be aligned, as shown herein, or they may be staggered. Either form is satisfactory.

Whereas the preferred form of the invention has been shown and described herein, it should be realized there are many modifications, substitutions and alterations thereto the scope of the following claims.

I claim:

1. An insulated wheel for use on railroad track or the like including a cylindrical metal rim having .a generally continuous flangeiaround its outer periphery and an enlarged internal bore, a metal hub positioned within the bore and having an outer diameter less than the diameter of the bore, the outer surface of the hub and the inner surface of the rimhaving generally equally and eral-ly rigid plastic tainnulu-s filling the cavity between the rim and hub and providing an interlock there'between.

'2. The structure of claim -1 further characterized in that said plastic annulus includes polyurethane.

References Cited in the file of this patent UNITED STATES PATENTS 7 1,948,304 7 Maas Feb. 20, 1934 6 I Krotz Sept. 10, 1946 Smith May 9, 1950 Coo-inbes Apr. 10, 195-1 Wetter Nov. 17, 1953 Beare -1- Dec. 16, 1958 Renter et a1. ,Iuly 2-7, 1959 FOREIGN PATENTS Great Britain 1892 Norway July 4, 1932 

1. AN INSULATED WHEEL FOR USE ON RAILROAD TRACK OR THE LIKE INCLUDING CYLINDRICAL METAL RIM HAVING A GENERALLY CONTINUOUS FLANGE AROUND ITS OUTER PERIPHERY AND AN ENLARGED INTERNAL BORE, A METAL HUB POSITIONED WITHIN THE BORE AND HAVING AN OUTER DIAMETER LESS THAN THE DIAMETER OF THE BORE, THE OUTER SURFACE OF THE HUB AND THE INNER SURFACE OF THE RIM HAVING GENERALLY EQUALLY AND AXIALLY SPACED CIRCUMFERENTIALLY EXTENDING LUGS, THE OUTER DIAMETER OF THE LUGS ON THE HUB SURFACE BEING LESS THAN THE INNER DIAMETER OF THE LUGS ON THE RIM SURFACE, THE LUGS ON THE HUB SURFACE AND THE LUGS ON THE RIN SURFACE BEING STAGGERED AND SPACED, RELATIVE TO EACH OTHER, SUCH THAT THE CAVITY BETWEEN THE INNER SURFACE OF THE RIM AND THE OUTER SURFACE OF THE HUB HAS A GENERALLY CONSTANT RADIAL THICKNESS THROUGHOUT, GENERALLY CIRCUMFERENTIALLY SPACED AXIALLY EXTENDING GROOVES IN THE OUTER SURFACE OF THE HUB AND THE INNER SURFACE OF THE RIM, SAID AXIALLY EXTENDING GROOVES BEING IN RADIAL ALIGNMENT, AND A GENERALLY RIGID PLASTIC ANNULUS FILLING THE CAVITY BETWEEN THE RIM AND HUB AND PROVIDING AN INTERLOCK THEREBETWEEN. 